Remove the heater inlet pipe, with heater hose, from the lower intake manifold and reposition aside.

Remove the radiator inlet hose from the engine.

Remove or disconnect the following:

CAUTION

Keep components separated in order to reinstall in the same location.

Water outlet

Thermostat

Lower intake manifold bolts

Lower intake manifold

Valve rocker arms and pushrods

Lower intake manifold gaskets and seals

Fig. Removing/installing the fuel rail assembly

Fig. Removing lower intake manifold and gaskets

To install:

Install or connect the following:

NOTE

The intake pushrods are identified with yellow stripes and are
3-5
/
4
inches long. Exhaust pushrods are identified with green stripes and are 6 inches long.

NOTE

With gaskets and seals in place apply a small drop of RTV sealer or equivalent, to the 4 corners of the intake manifold to block joints (1).

NOTE

Maximum gasket performance is achieved when using new fasteners that contain a thread locking patch. If the fasteners are not replaced, a thread locking chemical must be applied to the fastener threads. Failure to replace the fasteners or apply a thread-locking chemical MAY reduce gasket sealing capability.

CAUTION

Failure to tighten vertical bolts before the diagonal bolts may cause an oil leak

Lower intake manifold gaskets

Valve rocker arms and pushrods

Lower intake manifold

Fig. Lower intake manifold torque sequence-3.5L and 3.9L engines

Install and tighten the new lower intake manifold bolts in sequence as follows:

Tighten the lower intake manifold bolts in sequence to 115 inch lbs. (13 Nm) on the first pass.

Tighten the lower intake manifold bolts (1, 2, 3, and 4) in sequence to 15 ft. lbs. (20 Nm) on the final pass.

Tighten the lower intake manifold bolts (5, 6, 7, and 8) in sequence to 18 ft. lbs. (25 Nm) on the final pass.

Do not use solvent of any type when cleaning the gasket surfaces on the intake manifold and the throttle body assembly, as damage to the gasket surfaces and throttle body assembly may result. Use care in cleaning the gasket surfaces on the intake manifold and the throttle body assembly, as sharp tools may damage the gasket surfaces.

Clean and inspect the throttle body gasket mating surfaces.

To install:

If removed, install the throttle body to the upper intake manifold, as follows:

Install a new gasket, if necessary.

Install the throttle body assembly.

Install the throttle body nuts and the bolts. Tighten the nuts and the bolts to 89 inch lbs. (10 Nm).

Reposition the transmission dipstick tube and install the mounting bolt.

Install the alternator bracket to the manifold.

Reattach the heater pipes to the mounts on the intake manifold and tighten the nuts to 89 inch lbs. (10 Nm).

Install the left side spark plug wires.

Install the air intake assembly.

Connect the wiring harness to the following electrical connectors:

Intake manifold tuning valve

ETC

EVAP purge solenoid

MAP sensor

Install the PCV foul air and fresh air tube.

Install the intake manifold cover.

Refill the cooling system to the correct level.

Connect the negative battery cable.

Start the engine and check for leaks.

Lower Manifold

This engine uses a 2-piece intake manifold. The upper half (often called a plenum) mounts the throttle body. The lower half of the manifold bolts to the engine and contains the fuel injectors. Please note that this engine uses a sequential multi-port fuel injection system. Injector connectors must be connected to their appropriate fuel injector assembly or engine emissions and engine performance will be seriously affected. Identify and tag for identification all wiring connectors as well as vacuum and other components as required to assure correct assembly.

Before servicing the vehicle, refer to the Precautions Section.

Drain the engine coolant.

Relieve the fuel system pressure using the recommended procedure.

Remove or disconnect the following:

NOTE

Do not disconnect the power steering pipes or hoses from the steering pump.

Negative battery cable

Upper intake manifold

Left side valve rocker arm cover

Right side valve rocker arm cover

Wire harness from the Engine Coolant Temperature (ECT) sensor

Fuel injector, Manifold Absolute Pressure (MAP) and ECT wire harness

Fuel feed and return pipe from the injector rail

Fig. Remove the fuel injector rail

Fuel injector rail

Power steering pump from the front cover

Heater inlet pipe with the heater hose from the lower intake manifold

Radiator inlet hose

Thermostat bypass hose from the manifold

Lower intake manifold

Fig. Lower intake manifold assembly

Fig. Lower intake manifold assembly torque sequence

Pushrods after loosening the rocker arms

Lower intake manifold gasket and seals

ECT sensor, if replacing the manifold

Thermostat and housing, if replacing the manifold

To install:

Clean the gasket mounting surfaces.

Inspect the intake manifold for cracks or damage, replace if necessary.